Command Explanations

sed -i -e ...
scaffold.c: This command removes an obsolete C
declaration which causes the build to fail if using GCC-3.4.x.

Configuring Tcpwrappers

Config Files

/etc/hosts.allow and /etc/hosts.deny

File protections: the wrapper, all files used by the wrapper, and
all directories in the path leading to those files, should be
accessible but not writable for unprivileged users (mode 755 or
mode 555). Do not install the wrapper set-uid.

As the root user, perform the
following edits on the /etc/inetd.conf
configuration file:

finger stream tcp nowait nobody /usr/sbin/in.fingerd in.fingerd

becomes:

finger stream tcp nowait nobody /usr/sbin/tcpd in.fingerd

Note

The finger
server is used as an example here.

Similar changes must be made if xinetd is used, with the emphasis being on
calling /usr/sbin/tcpd instead of calling the
service daemon directly, and passing the name of the service
daemon to tcpd.